Piston rod



FIG. 1 is a perspective view of a piston rod.

FIG. 2 is a side elevational view of a first side of the piston rod.

FIG. 3 is a side elevational view of a second side of the piston rod.

FIG. 4 is a side elevational view of a third side of the piston rod.

FIG. 5 is a side elevational view of a fourth side of the piston rod.

FIG. 6 is a top plan view of the piston rod; and,

FIG. 7 is a bottom plan view of the piston rod.

The broken lines in the Figures depict environmental subject matter onlyand form no part of the claimed design.

CLAIM The ornamental design for a piston rod, as shown and described.